The subject of Volume XIX of The Light and the Dark is the history of the Byzantine Empire from 642 to 1453. The general theme of the whole series is 'dualism', in short the impact of unsolvable oppositions on historical societies; this is also the subject of this volume: unsolvable oppositions in Byzantine history, in its interior policy as well as in the relationships with the surrounding nations and with Latin Europe. The concentration on this overall theme implies that many important aspects of Byzantine history are not discussed; for these the reader must turn to the existing general histories of the Byzantine Empire. Notes with references to sources and literature can be found after each chapter. There are also a Bibliography and a General Index at the back of the book. After the Preface there is a Manual, in which the reader can find, per volume and chapter, the subjects treated in the previous eighteen volumes. At the back there is also a Chronology of the history of the
